A manual of anatomy . ide. Itrests upon the median longitudinal fasciculus and lies close to themidline. The axones arising from these cells pass downward (cau- THE OCULOMOTOR NERVE 447 dally) and laterally along the edge of the aqueduct gray which theyfollow to the midline; here the nerves decussate at the upper edgeof the superior medullary velum and emerge at the medial borderof the brachia conjunctiva. They are the smallest of the cerebralnerves. These nuclei receive fibers from the motor area of theopposite cerebral cortex through the pyramid. Fibers of the medianlongitudinal fasciculus a
A manual of anatomy . ide. Itrests upon the median longitudinal fasciculus and lies close to themidline. The axones arising from these cells pass downward (cau- THE OCULOMOTOR NERVE 447 dally) and laterally along the edge of the aqueduct gray which theyfollow to the midline; here the nerves decussate at the upper edgeof the superior medullary velum and emerge at the medial borderof the brachia conjunctiva. They are the smallest of the cerebralnerves. These nuclei receive fibers from the motor area of theopposite cerebral cortex through the pyramid. Fibers of the medianlongitudinal fasciculus also end here. The trochlear nerve arises from the midbrain just behind the cor-pora quadrigemina. It passes to the ventral surface of the brainstem and through the middle fossa of the skull to enter the orbitalfossa through the superior orbital fissure. It supplies the m. ob-liquus superior. The Oculomotor Nerve (Nervus Oculomotorius).—This is also apure motor nerve and its nucleus of origin is also in the Fig. 320.—Nuclei of origin of the motor cerebral ner\-es (lateral view). The nucleus is quite large, 5 to 6 mm. long and lies in the floor ofthe aqueduct gray substance under the superior quadrigeminalbodies just ahead of the preceding nucleus; it rests upon the medianlongitudinal fasciculus. The cells do not form a single mass butare arranged into a number of fairly distinct groups (at least seven)in each nucleus and a common small nucleus in the midline, thecentral nucleus. Most of the fibers of each nerve arise from thenucleus of the same side and pass ventrally in bundles; when the rednucleus is reached they spread out and pass through it, to be gatheredinto compact bundles at its ventral limit. These bundles are thencollected into a single mass that emerges upon the medial aspect ofeach cerebral peduncle (intercrural space) in the oculomotor sulcus(the groove between the crusta and tegmentum of the crus). 448 THE NERVE SYSTEM The fibers from the central nu
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecthumananatomy, bookyea
